1. Field of the Invention
The present invention pertains to the field of medicine. More specifically, the invention comprises a new user interface for controlling one or more surgical robots.
2. Description of the Related Art
Surgical techniques have evolved from “open” procedures in which the surgeon's hands entered the patient's body to endoscopic procedures in which a relatively small incision is made and visualization and manipulation tools are inserted through the incision into the body. The term “endoscopic” is used because visualization of the surgical site is provided via the insertion of a small optical device (originally some type of fiber optic image transmitter and now more commonly a small electronic camera).
The surgical tools that are used with endoscopic procedures tend to resemble older tools that were customarily used with open procedures. Although they are smaller, the end effectors and gripping portions of the endoscopic implements perform the same functions as their open predecessors. Tele-operated surgical robotic systems are now coming into widespread use, and these hold the promise of replacing the present endoscopic paradigm. Robotic surgical devices can provide greater accuracy and more degrees of freedom that a human-held endoscopic implement. However, the evolution away from open procedures to endoscopic procedures and ultimately to tele-robotic procedures is not without its drawbacks.
A surgeon performing an open procedure has the benefit of seeing precisely what his or her hands are doing. The surgeon can also feel the anatomical structures and the forces generated by the tools he or she is using. Some of these benefits were lost in the transition to endoscopic procedures. An even greater separation currently exists for tele-robotic procedures.
FIG. 1 shows a simplified depiction of a prior art robotic surgical apparatus 10. The device shown is similar to the DA VINCI surgical system marketed by Intuitive Surgical of Sunnyvale, Calif. Several support arms 18 are movably connected to column 16. Table 14 is also connected to column 16. The entire apparatus rests on base 12.
Table 14 may be movable in the x, y, and z axesto position the patient. One or more support arms 18 are movably attached to column 16. Joints 20 allows the support arms to articulate. Each support arm holds one or more end effectors 22. The end effectors are devices useful for medical procedures. Examples include electro-cautery devices, bone drills, and vascular clamps.
The actual end effectors may be quite small (millimeter-scale). They may also include one or more pivoting “wrists” near the end. This allows the end effector to be inserted through a small incision and then move in a variety of directions once inside the body. As those skilled in the art will know, the end effectors are capable of much more complex motion than would be possible with direct human manipulation of a passive device. In addition, the robotic surgical apparatus is able to move much more precisely than a human hand. The robotic surgical apparatus typically includes torque, position, velocity and strain sensors to maintain accurate closed-loop position and motion control.
Of course, a surgeon must control the robotic surgical apparatus. FIG. 2 shows a control station used for this purpose. Robotic control apparatus 24 is located remotely from the robot itself, though it will often be in the same room. Base 28 mounts stereoscopic view port 32, hand controller 30, and foot pedals 26. The surgeon typically sits in chair 44 in front of the control apparatus. A stereo endoscope on one of the robotic end effectors provides data to drive the stereoscopic view port 32. The surgeon places his or her eyes in front of the view port. The placement must be fairly close in order for the surgeon to adequately perceive the stereoscopic effect. The use of the stereoscopic view provides the surgeon with actual depth perception of the structures at the surgical site within the patient's body from a viewpoint fixed to the tip of the endoscope.
The surgeon controls the robotic end effectors primarily through the use of two hand controllers 30 and foot pedals 26. The use of the stereoscopic viewport and hand controllers compels the surgeon to sit in front of the control apparatus in a relatively fixed position. The controls themselves do not necessarily reflect the hand motions a surgeon is accustomed to making in an open or endoscopic procedure. FIG. 3 shows a prior art end effector 22 (a simple clamp). Movable jaw 38 moves toward fixed jaw 36 to clamp a desired object. Rotating joint 34 allows the movable jaw to be rotated about the roll axis to a desired orientation.
FIG. 4 shows one type of hand controller 30 that is used to control the operation of end effector 22. The surgeon moves grip 40 to adjust the position of the end effector. He or she then applies pressure to squeeze handle 42 in order to close movable jaw 38. It is possible to “map” the available control inputs to different functions so that a single input may be used to selectively control a variety of functions. A skilled surgeon may therefore use robotic control apparatus 24 to perform a wide variety of complex operations.
In studying the depiction of FIG. 2. however, the reader will appreciate a limitation inherent in this prior art approach. Traditional open surgery allowed the surgeon to be intimately in contact with the patient's anatomy. The surgeon employed the senses of sight, touch; and hearing to quickly gain and maintain situation awareness. As an example, a surgeon performing an open procedure might lean to one side to get a better look at a previously obstructed structure. This level of intuitive awareness was somewhat lost in the transition to endoscopic procedures. However, even for those procedures. the direct motions of the surgeon's hands translate to motions of the end effectors.
The robotic control apparatus shown in FIG. 2 presents a stark departure from the traditional paradigm. First, the surgeon is no longer near and oriented with respect to the patient. Second, there is no physical connection between the surgeon's hands and the end effectors. In fact, control software interprets the surgeon's input and uses that input to drive the motion of the selected effectors. In some aspects this “fly by wire” approach is beneficial (such as in smoothing out a trembling hand motion). But it fails to provide veridical force feedback, proprioception, and other useful sensations. Further, the prior art technique forces the surgeon to sit in an essentially static position. Robotic tele-surgery is presently recognized to be slower than comparable endoscopic procedures. Thus, the surgeon may be forced to remain in the static position for several hours.
On the other hand, tele-robotic surgery offers the advantage of not requiring a surgeon to actually be present at the site of the patient. In some instances this may be a great advantage. For example, a combat casualty could be treated by a variety of specialized surgeons who are not physically present. Each specialist only needs the ability to interface with the robotic surgical apparatus.
A better solution would combine the beneficial aspects of tele-robotic surgery with the more intuitive control environment of open and endoscopic procedures. The present invention seeks to provide such a solution.